1. Field of the Invention
The invention concerns a radiation detector for acquisition of radiation of the type having a semiconductor layer on a substrate, overlaid with a converter layer, the semiconductor layer being a component of a detector array that includes a number of detector elements, for spatially-resolved detection of radiation that is incident on the detector array.
2. Description of the Prior Art
Radiation detectors for x-ray radiation are known from “Digitale Detektorsysteme für die Projektionsradiographie” from Fortschr. Röntgenstr. 2001 (RöFo 2001), volume 173, pages 1137 to 1146, Theime Verlag, Stuttgart. In the known radiation detectors a semiconductor layer accommodated on a substrate is overlaid by a converter layer. The semiconductor layer is produced from amorphous silicon and is a component of a detector array with a number of detector elements. A transistor is associated with each detector element as a switching element for serial acquisition of the signals. The analog signals exhibit a significant noise level. The noise level makes the acquisition of weak signals particularly difficult.
In order to expose the patient to less radiation, it is sought to keep the dose power low. As a consequence, the signals supplied by the detector elements are sometimes very weak. For an optimally precise acquisition of such weak signals it is necessary that the sensitivity of the detector elements being increased.